One of the most important task for chemists is the development of new technology for producing energy and chemicals from sustainable resources. Plant derived biomass provides an ideal alternative to fossil resources, which is diminishing very rapidly and lots of efforts have been devoted to the conversion of bio mass to diverse molecules that can be used to produce energy feedstock chemicals and fine chemicals such as n-butanol, ethanol, sorbitol, hydroxymethylfurfural, methylfurfural, γ-valerolactone (GVL). The γ-valerolactone is considered an interesting green, bio-based platform chemical with high application potential. The development of environmentally benign, cost effective process for the synthesis of GVL has received extensive attention in recently years. Although there have been reports for the hydrogenation of leuvlunic acid using molecular hydrogen or formic acid over homogeneous or heterogeneous catalysts but most of the cases the reaction temperature is very high. The main advantage of our process is that reaction was carried out at room temperature to get very high yield.
Reference can be made to the article in Green Chem 14, 2012, 2057-2065 by J M Tukacs et al. where they used molecular hydrogen in the presence of Ru(acac)3 as homogeneous catalyst at 100 bar hydrogen pressure and 140° C.
Reference can be made to the article in Fuel 115, 2014, 101-108 by Kai Yan et al. where they reported 98.7% conversion of levulinic acid with 90.1% selectivity for GVL over Cu—Fe catalyst using 70 bar of hydrogen at 200° C.
Reference can be made to the article in Rsc Adv. 3, 2013, 3858-3856 by Kai Yan et al. where they reported >99% conversion of levulinic acid with 90.7% selectivity for GVL over Cu—Cr catalyst using 60 bar of hydrogen also.
Reference can also be made to the article in Green chem. 2014, 16, 4092-4097 by Estevao F Mai et al. where >99% conversion of levulinic acid with 90% selectivity for GVL is reported over Mo2C/CNT catalyst using 30 bar of hydrogen at 200° C.
Reference can be made to the article in Green Chem. 14, 2014, 1064-1072 by C. V. Rode et. al where they reported 100% conversion of levulinic acid with 100% selectivity for GVL over Cu—ZrO2 (1:1) catalyst using 34.5 bar of hydrogen at 200° C.
Reference can also be made to the article in Energy & Environ Sci. 6, 2013, 3308-3313 by Yong Cao et al. where they reported is that 100% conversion of levulinic acid with 100% selectivity for GVL over 20% Cu—ZrO2 catalyst using 40 bar of hydrogen at 200° C.
Reference can also be made to the article in Green Chem. 2014, 16, 3899-3903 by Ken-ichi Shimizu et al. to get 100% conversion of levulinic acid with 97% selectivity for GVL over Ni—MoOx/C catalyst using 8 bar of hydrogen at 140° C. in 5 hours reaction time.
Reference can be made to the article in RSC Adv. 2014, 4, 13481-13489 by J Wang et al. where they used Zr-Beta Zeolite as a robust catalyst for liquid and gas phases hydrogenation of Levulinic acid with 96% selectivity in batch reactor around 99% selectivity of GVL was obtained in continuous flow reactor using hydrogen donor at ambient pressure and solvent boiling temperatures.
Reference can be made to the article in Green Chem. 2012, 14, 688-694 by A M R Galletti et al. where they reported the levulinic acid to GVL at 70° C. using 5 bar hydrogen pressure but in the presence of 5% Ru/C combination of acid co-catalyst like Amberlytst A70, Amberliyst A 15, niobium phosphate and niobium oxide. Levulicnic acid hydrogenation was also studied with the combination of Ru/C and Amberlyst A70 at 50° C. and conversion was reported as 85% and with 99.1% selectivity of GVL.
Reference can be made to the article in Applied Catal. A: General, 2015, 491, 127-135 by Praveen P Upare et al. where Nickel-promoted Copper-Silica nano composite catalyst was used for leuvlunic acid hydrogenation using formic acid as a hydrogen source. The catalyst selectively converts 99% of LA in to 96% GVL. The reaction was carried at 265° C. at 1 atm pressure in continues down flow reactor.
Reference can be made to the article in Green Chem., 2014, 163870-3875 by H Zhou et al. where they reported Co3O4 as the catalyst for the conversion of ethyl levulinate to γ-valerolactone at 130° C. and 33 bar H2 bar hydrogen pressure.
Reference can be made to the article in Green Chemistry., 2012, 14, 3336-3343 by Zhijie Wu et al. where the combination of hydrolysis reaction and hydrogenation/hydrogenolysis of cellulose to GVL by MCM-41-1.5-SO3—H and Ru/C is reported at 230° C. and 6 bar hydrogen pressure in sequentional process and single pot process. In both cases selectivity of GVL was obtained around 95%. But MCM-41-n-SO3 was deactivated after reaction.
In all the above cases the reaction temperature was very high. The advantage of our catalyst is to produce γ-valerolactone at room temperature.